I tried to generate a mesh for considerebly complexed geometry
but I got the following errors and warnings
1) Error: The following surfaces cannot be meshed with acceptable quality. Try using a different element size or virtual topology.

2) Warning: The following surface or surface bounds may have incorrect orientation

3)Warning: The advanced size function failed to initialize the following topologies.

4)Error: A mesh could not be generated using the current meshing options and settings. Hint: The problem geometry areas might have been highlighted. Switching to wireframe mode may make them more visible.